Vegetable Leafminer Control on Tomato, 1977

Beginning about 10 days before first harvest, insecticidal treatments were applied weekly to ‘Walter’ tomato plants in a commercial field in Hillsborough County, Florida. Plants were approximately 25% defoliated by ihe vegetable leafminer at first spray. Treatments were applied to runoff with a hand-held, 7.6-liter sprayer at 13.6 to 18.1 kg/6.5 cm pressure. Plots were seep irrigated and consisted of 5 plants 0.8 m apart grown on black polyethylene plastic mulched sand beds (0.8m wide by 0.2 m high) 1.8 m apart. Four replications were arranged in a randomized complete block design. Plots were treated April 28, May 5, 12, 19, 26, and June 2, 1977. The number of mines were counted on the first trifoliate (terminal 3 leaflets) from the top of 10 stems per plot on May 12. The percent defoliation on each plant on June 9 was calculated by dividing the approximate height of defoliation (defoliation progresses upward from the base of the plant) by the approximate height of the plant and multiplying by 100. Yields of marketable fruit (grades 1, 2, and 3), obtained on May 12, 19, 26, June 2, and 9, were combined over all dates and converted to yield per acre for analysis.